Where's the rainy season? It might arrive by next week

Ken KayeSun Sentinel

So where’s the rainy season? It was supposed arrive last Friday, or at least May 20 is the average date that it starts.

But for the past several days a deep layer of high pressure stretching from Mexico, across the Gulf of Mexico and over Florida has blocked moisture from building up in the atmosphere, the National Weather Service in Miami said.

The good news: That high pressure system might weaken or move enough to create some instability in the atmosphere and allow moisture to flow in from the east, said meteorologist Roberto Garcia.

That means the five-month rainy season, when South Florida sees 70 percent of its annual rainfall, is “on the way,” he said.

As an indicator of that, the rain chance increases to 30 percent on Friday, and some weather forecasting models predict a sharp increase in rain amounts by next week, he said.

In the meantime, South Florida remains under extreme drought conditions. Since Jan. 1, Fort Lauderdale has received 4 inches of rain, 12.7 below normal; West Palm Beach has received 5 inches of rain, 12.2 below normal and Miami 11.3 inches of rain, or about 2.4 inches below normal.

Normally, the weather service declares rainy season is here when dew-point temperatures reach 70 degrees, a major signal that the atmosphere is loaded with moisture.

This year, however, the moisture just hasn’t built up.

“This has probably been the strangest start to the rainy season that I can remember,” said meteorologist Robert Molleda, whose job it is determine when, exactly, the rainy season starts.

“I've been waiting for the precipitation and moisture levels to increase to a point where it's obvious that it has started,” he said. “Most years we can rely on this, but this year I'm afraid we're going to slowly slide into the rainy season with only subtle indicators.”

Some of those indicators include thunderstorms over the Everglades and the ocean, he said.

Possibly, Molleda will determine that Friday is the starting date of the season. Or he might have to wait until sometime next week to make the announcement. For those with thirsty lawns and plants, it can’t be soon enough.